Flight data monitoring (FDM) is the routine collection and analysis of flight data recorded during normal operations, used to find and reduce safety risk. ICAO calls the practice flight data analysis, and the FAA calls it flight operational quality assurance (FOQA). ICAO and EASA require a programme for operators of aeroplanes with a maximum take-off mass over 27 000 kg. In the United States, FOQA is voluntary.
One practice, three names
| Term | Used by | Official wording |
|---|---|---|
| Flight data analysis (FDA) | ICAO, Annex 6 | "A process of analysing recorded flight data in order to improve the safety of flight operations." |
| Flight data monitoring (FDM) | EASA and the UK CAA | "The proactive and non-punitive use of digital flight data from routine operations to improve aviation safety." |
| Flight operational quality assurance (FOQA) | FAA | "An FAA-approved program for the routine collection and analysis of digital flight data gathered during aircraft operations." |
The regulators treat these as the same practice. The FAA describes FOQA as "the FAA equivalent to FDA", and the UK CAA's guidance describes FOQA as the FAA's term for flight data monitoring. The differences are in who must run a programme and how the data is protected.
How an FDM programme works
Aircraft record flight parameters continuously on every flight. An FDM programme takes that recorded data after each flight, converts it into engineering values, and looks for the flights and trends that deserve attention. EASA's acceptable means of compliance describe three analysis techniques.
| Technique | What it does | Example |
|---|---|---|
| Exceedance detection | Searches for deviations from aircraft flight manual limits and standard operating procedures. | An approach that is not stabilised by the operator's gate, or a landing above a vertical-acceleration threshold. |
| All-flights measurement | Measures the same parameters on every flight to define what normal practice is. | The distribution of touchdown points or approach speeds across the fleet. |
| Statistics | Collects series of data to support analysis and show trends. | Event rates by airport, runway, aircraft type, or month. |
An analyst then checks that a detected event is real, since a sensor fault or a decoding error can look like an exceedance. Validated events are assessed for risk and passed to the safety management system, where they can lead to a procedure change, targeted training, or an engineering action.
The people in the programme
EASA guidance describes an FDM team that includes a team leader, flight operations and technical interpreters, engineering support, and a gatekeeper. The safety manager is responsible for identifying and assessing the issues the programme finds.
Who must have a programme
| Framework | Who it covers | Status |
|---|---|---|
| ICAO Annex 6, Part I | Operators of aeroplanes with a maximum certificated take-off mass over 27 000 kg. | Standard: the operator "shall establish and maintain a flight data analysis programme as part of its safety management system." |
| ICAO Annex 6, Part I (Amendment 49) | Aeroplanes over 15 000 kg with more than 19 passenger seats and a certificate of airworthiness first issued on or after 1 January 2027. | Standard: the aeroplane must be equipped to support a programme, and its operator runs one. |
| ICAO Annex 6, Part I | Operators of aeroplanes over 15 000 kg. | Recommended practice. |
| EASA, ORO.AOC.130 | Aeroplanes with a maximum certificated take-off mass of more than 27 000 kg. | Required, integrated in the operator's management system. |
| EASA, SPA.HOFO.145 | Commercial offshore helicopter operations with a helicopter equipped with a flight data recorder. | Required. |
| United Kingdom | The same 27 000 kg rule, retained in UK law. CAP 739 is the CAA's good-practice guidance. | Required. |
| Canada | Subpart 705 operators conducting international scheduled operations. | Transport Canada states that it has adopted the ICAO standard. |
| United States | No operator. The FAA states: "No aircraft operator is required to have a FOQA program." | Voluntary. |
ICAO lowered its thresholds with Amendment 49 to Annex 6, applicable from 28 November 2024. Material that still cites a 20 000 kg recommendation predates that change. National rules implement the ICAO standards on their own timetables, so an operator should confirm the requirement with its authority.
Protecting the data and the crew
A programme only works if crews trust it. The rules therefore protect the source of the data.
- EASA. The programme "shall be non-punitive and contain adequate safeguards to protect the source(s) of the data." The procedure that prevents disclosure of crew identity should be written down and signed by all parties.
- ICAO. The programme must contain adequate safeguards to protect the sources of the data, in line with the protection principles of Annex 19.
- United States. Under 14 CFR 13.401, the FAA will not use data from an FAA-approved FOQA program in an enforcement action against the operator or its employees, except for criminal or deliberate acts.
In EASA guidance the gatekeeper "is the only person permitted to connect the identifying data with the event." Analysts work with de-identified flights, and identity is released only through the agreed procedure.
How FDM fits the safety management system
Flight data monitoring is a data source for the safety management system, not a separate activity. ICAO requires the programme "as part of" the operator's SMS, and EASA requires it to be "integrated in its management system". The FAA describes FOQA as "another potential tool in an aviation organization's SMS to monitor operational data and provide data analysis and assessment."
In practice, FDM supplies the safety assurance component with measured evidence: whether a risk control changed the event rate, where a new hazard is emerging, and whether a procedure is flown as written.
What to check in FDM software
- Traceable decoding. Can an analyst see which decoder, dataframe, and event definition produced a result?
- Data quality. Are decode gaps and invalid samples shown separately from operational events?
- Event definitions under review. Who can change a threshold, and is the change tested against past flights before it takes effect?
- Crew identity. Is de-identified analysis separated from identity records, with gatekeeper-controlled access?
- Analyst workflow. Can the analyst move from the event to the synchronized traces and record a reviewed conclusion?
- Connection to the SMS. How does a validated event become a safety record with an owner and an action?
PHAROS is FlightAtom's flight data monitoring software. It is in development: demonstrations use synthetic flights, and aircraft layouts, thresholds, and outputs require operator validation before operational use.
Official references and scope
These sources define and explain flight data monitoring requirements. They do not certify any product, and the applicable rule depends on the operator and its authority.
- EASA Easy Access Rules for Air Operations: Regulation (EU) No 965/2012 with ORO.AOC.130, SPA.HOFO.145, and the related acceptable means of compliance and guidance material.
- 14 CFR 13.401: the FAA rule on flight operational quality assurance programs and the protection of FOQA data.
- FAA Advisory Circular 120-82: FAA guidance on flight operational quality assurance.
- UK CAA CAP 739, Flight Data Monitoring: CAA good-practice guidance on establishing and running an FDM programme.
- ICAO Council adoption of Annex 6 amendments: ICAO announcement of the 2024 amendments that expanded the flight data analysis programme.
- Transport Canada Advisory Circular 700-068: Transport Canada guidance on flight data monitoring programmes.
Flight data monitoring FAQs
What does FDM stand for in aviation?
FDM stands for flight data monitoring: the proactive use of digital flight data from routine operations to improve safety. ICAO uses the term flight data analysis, and the FAA uses flight operational quality assurance (FOQA) for the same practice.
Is FDM the same as FOQA?
In practice, yes. The FAA describes FOQA as its equivalent of flight data analysis, and the UK CAA describes FOQA as the FAA term for flight data monitoring. The regulatory position differs: FOQA is voluntary in the United States, while ICAO and EASA require a programme for larger aeroplanes.
Is flight data monitoring mandatory?
Under ICAO Annex 6 and EASA rule ORO.AOC.130, operators of aeroplanes with a maximum certificated take-off mass over 27 000 kg must establish and maintain a programme. In the United States, no operator is required to have a FOQA program.
Which aircraft need a flight data monitoring programme?
ICAO requires a programme for aeroplanes over 27 000 kg, and for aeroplanes over 15 000 kg with more than 19 passenger seats whose certificate of airworthiness is first issued on or after 1 January 2027. It recommends one for all aeroplanes over 15 000 kg. EASA requires one for aeroplanes over 27 000 kg and for commercial offshore helicopter operations with a helicopter equipped with a flight data recorder.
Can FDM data be used to discipline pilots?
EASA requires an FDM programme to be non-punitive and to protect the sources of the data. In the United States, the FAA will not use data from an approved FOQA program in enforcement action, except for criminal or deliberate acts.
What is an FDM gatekeeper?
The gatekeeper is the member of the FDM team who protects crew identity. EASA guidance describes the gatekeeper as the only person permitted to connect identifying data with an event.
What does FDM software do?
FDM software decodes recorded flight data, detects events and exceedances against defined limits, measures normal operations across all flights, and supports analyst review. PHAROS is FlightAtom's FDM software, currently in development.
See how PHAROS approaches flight data
PHAROS is in development with traceable decoding, event review, and crew-identity controls. Bring a representative question from your programme and see the current analyst workflow with synthetic flights. Explore PHAROS.